1. Field of the Invention
The present invention relates to a solenoid valve device in which a plurality of solenoid valves each comprising a valve part whose tip end is fitted in a fixed mounting block and a solenoid part whose tip end is continuously provided at the rear end of the valve part are fixed to the mounting block, and connection terminals, each of which is connected to the solenoid part of the respective solenoid valves, are placed inside a common coupler.
2. Description of the Prior Art
Such a solenoid valve device is known in the art in, for example, Japanese Patent Application Laid-open No. 63-180550, in which a coupler is integrally formed with a synthetic resin cover which is mounted on a mounting block so as to cover each of the solenoid valves, a plurality of connection terminals, parts of which are buried in the cover, are placed inside the coupler and each of the connection terminals is connected to the solenoid part of the respective solenoid valves via a lead wire.
However, in the above-mentioned solenoid valve device of the art, when the solenoid valve device is assembled it is necessary to connect each of the lead wires by means of soldering, etc., the assembly performance is poor and the number of assembly steps increases, and there is a possibility that erroneous connection of the lead wires might occur. Moreover, since the cover is applied to the solenoid valves subsequent to the connection via the lead wires, the lead wires need to have a length longer than that required for the connection, it is necessary to carefully attach the cover to the mounting block so that the extra length of the lead wires is not trapped between the cover and the mounting block, and thus the assembly operation becomes complicated. Furthermore, it is necessary to undo the connection of the lead wires during maintenance such as that involving replacement of the solenoid valves, and thus the maintenance operation also becomes complicated.
The present invention has been carried out in view of the above-mentioned circumstances, and it is an object of the present invention to provide a solenoid valve device in which a solenoid part of each of solenoid valves and each of connection terminals inside a coupler can be connected and disconnected extremely easily and, moreover, no erroneous connection can occur.
In order to achieve the above-mentioned object, according to a first aspect and feature of the present invention, a solenoid valve device is provided in which a plurality of solenoid valves each comprising a valve part whose tip end is fitted in a fixed mounting block and a solenoid part whose tip end is provided continuously at a rear end of the valve part are fixed to the mounting block, and connection terminals, each of which is connected to the solenoid part of the respective solenoid valves, are placed inside a common coupler, wherein a coupler assembly integrally provided with the coupler is detachably mounted on the mounting block at a position which is spaced back from each of the solenoid parts, a plurality of electrically conductive lead members, each of which has one end connected to the connection terminals respectively, are arranged in the coupler assembly, and elastic connecting members made from an electrically conductive metal are respectively interposed between a plurality of first flat terminals, each of which is connected to the other end of the corresponding lead member and fixedly positioned on the side of the coupler assembly facing the mounting block, and second flat terminals which are arranged at the rear ends of the respective solenoid parts so as to be individually opposite the first flat terminals.
In accordance with the above-mentioned arrangement of the first feature, each of the connection terminals inside the coupler can be individually connected to the solenoid part of the respective solenoid valves simply by mounting the coupler assembly on the mounting block so as to provide an elastic connecting member between the respective first and second flat terminals, there is no need to connect the lead wires during assembly, and when carrying out maintenance such as replacement of each of the solenoid valves the coupler assembly may be demounted from the mounting block and there is no need to disconnect the lead wires. Therefore, it is possible to enhance the operational efficiency by carrying out the connection and disconnection between the solenoid part of each of the solenoid valves and the corresponding connection terminals inside the coupler with great ease so simplifying the assembly and maintenance operations. Moreover, there is no possibility of erroneous connection of the lead wires and there is no need to take care over trapping of the lead wires. Furthermore, the elastic connecting members can absorb a displacement of the relative positions of the mounting block and the coupler assembly and form a reliable electrical connection between the first and second flat terminals, it is unnecessary to enhance the assembly accuracy with which the coupler assembly is mounted on the mounting block, and the coupler assembly can be easily mounted on the mounting block.
Furthermore, in addition to the above-mentioned first feature, according to the second aspect and feature of the present invention, the coupler assembly is comprised of a first body made from a synthetic resin integrally provided with the coupler and a second body made from a synthetic resin which is mounted on the first body such that they overlap each other, wherein said lead members which each have one end connected to a plurality of said connection terminals respectively which are fixedly positioned inside the coupler, and the first flat terminals, each of which is connected to the other end of the lead members respectively, are arranged on the side of the first body facing the second body, and wherein insertion holes into each of which a part of each of the elastic connecting members is inserted are provided on the second body so as to correspond to the first flat terminals respectively.
In accordance with the above-mentioned arrangement of the second feature, the lead members are contained between the first and second bodies, it is thus possible to protect the lead members while rendering them electrically insulating, and by inserting part of the elastic connecting members into the insertion holes one end of the elastic connecting members can easily be guided to the first flat terminals.
Furthermore, in addition to the above-mentioned second feature, according to the third aspect and feature of the present invention, a plurality of recessed parts which house the first flat terminals respectively are provided on the side of the first body facing the second body, and a plurality of fitting projections, each of which is made in the form of a tube so as to form a part of each of said insertion holes, are projectingly provided on the second body so as to be capable of fitting in each of the recessed parts respectively and, in accordance with the above-mentioned arrangement, the relative position of the first and second bodies can reliably and easily be adjusted and the accuracy with which the elastic connecting members are guided by the insertion holes can be enhanced as a result of an increase in the length of the insertion holes by a length corresponding to that of the fitting projections.
Furthermore, in addition to the above-mentioned second or third feature, according to the fourth aspect and feature of the present invention, each of the insertion holes is made in the form of a tapered hole whose diameter increases as it goes towards the first body and each of the elastic connecting members is a conical coil spring whose larger diameter end is positioned on the side of the first body. With the above-mentioned arrangement, since the elastic connecting members do not drop from the insertion holes, no special arrangement to retain the elastic connecting members in the coupler assembly is necessary, and moreover the accuracy of positioning the elastic connecting members inside the insertion holes can be enhanced.
Furthermore, in addition to the above-mentioned second or third feature, according to the fifth aspect and feature of the present invention, a plurality of hooks which elastically engage with one of the first and second bodies are integrally provided on the other of the first and second bodies. With the above-mentioned arrangement, no special member such as a screw part for mounting the second body on the first body is necessary, and the second body can easily be mounted on the first body by means of a small number of parts.
The above-mentioned and other objects, features and advantages of the present invention will become apparent from an explanation of preferable embodiments which will be described in detail below by reference to the attached drawings.